Related Experiment Video
Updated: Dec 13, 2025
11:33
All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
10.1K
Fast low-noise transimpedance amplifier for scanning tunneling microscopy and beyond
Martin Štubian1, Juraj Bobek1, Martin Setvin1
1Institute of Applied Physics, TU Wien, 1040 Vienna, Austria.
The Review of Scientific Instruments
|August 6, 2020
Summary
A new transimpedance amplifier offers low noise and wide dynamic range for scanning tunneling microscopy (STM). It minimizes capacitance and noise, making it ideal for low-temperature STM and other applications.
Area of Science:
- Instrumentation and Measurement
- Materials Science and Engineering
Background:
- Scanning Tunneling Microscopy (STM) requires sensitive current amplifiers.
- Low-noise, wide dynamic range amplifiers are crucial for advanced STM applications.
Purpose of the Study:
- To design and characterize a novel transimpedance amplifier for STM.
- To address noise limitations and enhance performance in low-current measurements.
Main Methods:
- Design of a transimpedance amplifier with a 1 GΩ feedback resistor.
- Characterization of noise, bandwidth (50 kHz at 35 pF), and dynamic range (0.1 pA-50 nA).
- Analysis of noise sources, including operational amplifier input impedance effects.
Main Results:
- The amplifier achieves low noise, dominated by Johnson noise at low currents.
- Sufficient bandwidth (50 kHz) for typical STM operation.
- Wide dynamic range (0.1 pA-50 nA) without requiring range switching.
Conclusions:
- The designed transimpedance amplifier is well-suited for low-temperature STM applications.
- It offers significant advantages in noise reduction and dynamic range.
- Potential applications extend to scanning electron microscopy and photodiode amplification.
Related Concept Videos
01:23Small-Signal Analysis of MOSFET Amplifiers
958
In small-signal analysis, a MOSFET transistor amplifier acts as a linear amplifier when operating in its saturation region. The gate-to-source voltage (VGS) of the MOSFET is the sum of the DC biasing voltage and the small time-varying input signal. This combination sets up the operating point and modulates the drain current (ID) that flows from the drain to the source. When a small AC signal is superimposed on the DC bias voltage at the gate, the instantaneous drain current comprises three...
958
01:22Overview of Microscopy Techniques
14.5K
The early pioneers of microscopy opened a window into the invisible world of microorganisms. In 1830, Joseph Jackson Lister created an essentially modern light microscope. The 20th century saw the development of microscopes that leveraged nonvisible light, such as fluorescence microscopy that uses an ultraviolet light source and electron microscopy that uses short-wavelength electron beams. These advances significantly improved magnification, image resolution, and contrast. By comparison, the...
14.5K
01:21Small-Signal Analysis of BJT Amplifiers
1.5K
Small signal analysis is a fundamental approach used in electronics to understand how a Bipolar Junction Transistor (BJT) amplifier processes signals. In the active region, the BJT is designed for linear amplification. The transistor's behavior under these conditions is governed by its instantaneous base-emitter voltage VBE, a sum of the DC bias VBE, and a small AC signal VBE, resulting in the collector current iC. Here, the collector current has a DC component and an AC component.
1.5K
01:14BJT Amplifiers
840
Bipolar Junction Transistors (BJTs) are pivotal components in amplifier circuits, functioning as voltage-controlled current sources in their active region. This characteristic allows them to efficiently control the collector current through variations in the base-emitter voltage. Essentially, BJTs amplify power due to their ability to take a weak input signal and output a much stronger signal.
In BJT amplifier configurations, particularly in common-emitter setups, the transistor's role...
In BJT amplifier configurations, particularly in common-emitter setups, the transistor's role...
840
01:17MOSFET Amplifiers
379
The MOSFET, when operating in its active region, functions as a voltage-controlled current source. In this region, the gate-to-source voltage controls the drain current. This principle underlies the operation of the transconductance MOSFET amplifier. The output current is directed through a load resistor to convert this amplifier into a voltage amplifier. The output voltage is then obtained by subtracting the voltage drop across the load resistance from the supply voltage. This process results...
379